Ludwig mullee



L. MULLER.

(No Model.)

FILE.

No. 309,973. Patented Dec. 30, 1884.

INVENTOR ATTO NEYS.

WITNESSES K-EQMZ llrirTnn STATns PATENT @rricrz.

LUDIVIG MULLER, OF DRESDEN, SAXONY, GERMANY, ASSIGNOR TO OTTO XV.LOEFFLER, OF NEWV YORK, N. Y.

FILE.

SPECIFICATION forming part of Letters Patent No. 309,973, dated December30, 1884.

Application filed Xovember 1', 18M. (No model.) Patented in GermanyJanuary 1, 1884, No. 27,846; in Belgium May 30, 1884, No.

7 65,329, and in AustriaHungary July 30, 1884, No. 20,574 and No.34,261.

To aZZ whom, zit may cohcern:

Be it known that I, LUDWIG MiiLLER, of Dresden, in the Kingdom of Saxonyand Empire of Germany, have invented certain new and useful Improvementsin Files, (for which Letters Patent have heretofore been issued to me bythe following governments: Germany, No. 27,846, dated January 1, 1884;Belgium, No. 65,329, dated May 30, 1884, and Austria- Hungary, No.20,574 and No. 34,261, dated July 30, 1884,) of which the following is aspecification.

The invention relates to an improved construction of files, the teeth ofwhich can be conveniently sharpened without tempering on the surface ofa grindstone; and the invention consists of a file composed of a seriesof recessed steel plates or teeth,which are secured by clamps in asupporting frame having inwardly-projecting side flanges. For sharpeningthe cutting-edges of the teeth, the same are placed in an inclinedposition to the frame, and locked in this position by an interposedsteel plate or other suitable means, so as to be applied to agrindstonc.

In the accompanying drawings, Figure 1 represents a plan, Fig. 2 avertical longitudinal section, Fig. 3 a bottom view, and Fig. 4, avertical transverse section, of my improved file. Fig. 5 is a verticallongitudinal sect-ion showing the method of setting the teeth forsharpening the same, and Fig. 6 is a vertical transverse section of afile with double teeth or plates.

Similar letters of reference indicate corresponding parts.

In the drawings, 0 represents the supporting-frame of my file, which ismade of U- shaped cross section, and provided with inwardly-extendingflanges b'b. A series of steel plates or teeth, a a, are supported bythe frame 0, and provided at one side with vertical ribs, as shownclearly in Fig. 4. The steel plates or teeth (I. a have recesses attheir oppo-' site edges, said recesses being somewhat larger in sizethan the flanges b b of the supporting frame 0, so that the steel platesor teeth can be casilyinserted at the outer end of the frame and movedinto position along the flanges b b. In inserting the teeth the ribbedside should face the outer end. When the required number of teeth orplates have been inserted, the frame 0 is closed at-the outer end by astrong cheek, d, which is attached by fasteningserews c e. The steelplates or teeth are then firmly clamped to the frame 0 by means of ascrew, f, that is secured by a ferrule into a handle. 11, said screwhaving a crosshead, 9, at its outer end, that is guided in the frame, soas to press the steel plates or teeth firmly together.

To prevent the loosening of the clamping screw f, a set-screw, 1', isused, that presses a copper plate, 7;, tightly against the threads ofthe screw f, as shown in Fig. 2.

For sharpening the plates or teeth a a, the end cheek, (l, is removedand the plates placed in inclined position to the frame 0, which ispossible by means of the larger size of the side recesses of the same.The upper ends of the steel plates or teeth are thereby placed at somedistance from the transverse portion of the frame 0, so as to admit theinsertion of a steel plate, A, which serves to hold the steel plates orteeth in inclined position in the frame 0. The cutting edges of theteeth are placed by the change of position into one plane, so that theycan be readily sharpened on the grinds tone while held in position bythe plate A. \V hen the grind ing of the lower edge is completed, thesteel plate A is removed, and the teeth a a are returned into a positionat right angles to the supporting frame 0, and clamped by means of thecheck (1 and clamping screw f, as before described. \Vhen double teeth aa are used, as shown in Fig. 6, the same are centrally recessed andplaced on a center frame or stock, to which they are secured by a key orfeather, a. "When this key is removed, the teeth can be set and lockedinto inclined position to the stock, for being sharpened at bothcutting-edges on the grindstone, in the same manner as before described.It will thus be seen that the sharpening of the teeth of the file givesbut littletrouble, as it requires simply the change of position of theteeth from a position at right angles to the frame to an inclinedposition thereto and back again to the former position. The temper andthe hard ness of the teeth are thereby retained and a very effectivefile obtained for use inthe arts.

Havingthus described myinvention, I claim as new and desire to secure byLetters Patent- 1. The combination of the supporting-frame C, havinginwardly projecting flanges, a series of steel plates or teeth havingside reccsses, and means for clamping the teeth in the supporting-frame,substantially asset forth.

2. The combination of the supporting-frame 0, having inwardly projectingflanges, a series of steel plates or teeth having side recesses, adetachable cheek, (l, secured to the outer end, and clamping-screwf,having a cross-head, y, arranged at the opposite end of the frame,substantially as set forth.

In testimony that I claim the foregoing as myinvention I have signed myname in presence of two subscribing witnesses.

LUDWIG MULLER.

W'itnessesz. I

\VILi-IELM \VInsENn'ii'r'rER, GEORG RICHTER.

